1. Field of the Invention
An improved construction article of a combination of recycled waste materials is provided which is strong, resistant to decomposition and may be combined in interlocking relationship with other similarly configured articles. In particular, the invention hereof advantageously utilizes materials such as plastic, metal, paper, polystyrene foam, and glass which have long decomposition periods and the invention thus provides a means for converting what would otherwise be solid waste into a useable article.
2. Description of the Prior Art
The solid waste problem encountered throughout the world is well-known. The conventional solution to the disposal of solid wastes is the landfill, which effectively contaminates the soil against future use and makes the surrounding area undesirable for habitation. Several solutions have been proposed for eliminating or reducing the solid waste which is deposited in landfills. One proposed solution is the use of solid waste as fuel, thereby reducing its volume and generating energy as a by-product of waste disposal.
Unfortunately, a number of types of solid waste are not effectively dealt with by ordinary combustion processes. Glass, metal, and many plastics prove unsatisfactory fuels and yield residues which still must be disposed. Also, combustion of waste materials requires an intensive capital investment and must be accompanied by satisfactory environmental controls to prevent discharge of combustion byproducts to the atmosphere. As a result, landfills remain the most common solid waste disposal method.
These materials represent some of the common constituents of what is regarded as "municipal solid waste". Municipal solid waste (MSW) has been defined by the Environmental Protection Agency as including "wastes such as durable goods, nondurable goods, containers and packaging, food wastes, yard wastes, and miscellaneous inorganic wastes from residential, commercial, institutional and industrial sources." Examples of wastes from these categories include appliances, newspapers, clothing, food scraps, boxes, disposable tableware, office and classroom paper, wood pallets and cafeteria wastes. MSW does not include wastes from other sources, such as municipal sludges, combustion ash, and industrial non-hazardous processed wastes that might also be disposed of in municipal waste landfills or incinerators. According to 1988 nationwide figures, MSW includes the following constituents by weight:
______________________________________ Constituent Percent Tons in Millions ______________________________________ Paper 40% 71.8 Yard Wastes 17.6% 31.6 Metals 8.5% 15.3 Glass 7.0% 12.5 Plastics 8.0% 14.4 Other 11.6% 20.8 Food Wastes 7.4% 13.2 ______________________________________
A separate problem encountered by contractors has been the need for a low-cost construction article which can be used in low-stress environments. Contractors most often purchase new materials made of concrete for retaining walls, parking lot stops, and other applications where lesser materials than brick, cement or concrete would often suffice. These new materials are often relatively costly and require additional quarries for obtaining the raw materials.
There has thus developed a need for a low-cost, relatively high-strength material which could be used in construction environments. There has additionally developed a need for alternatives to landfill disposal of solid wastes.